Rats raised on a 6% protein diet (low-protein diet) for three weeks
have a reduced ability to synthesize collagen, and because the levels
of this diet-induced reduced collagen synthesis are comparable to
those for normally aged rats, low-protein diet-fed rats can be used
as a model for aged rats. In the present study, 6-week-old male Wistar
rats were raised on a low-protein diet for three weeks, and the effects
of applying 3,000 V of alternating current and supplementing the
low-protein diet with Eucommia ulmoides leaves on collagen synthesis
were determined. 1. By applying 3,000 V of alternating current to
the rats on the low-protein diet, the weight of granulation tissue
and levels of hydroxyproline increased in a time-dependent manner
when compared with the control group. After six weeks of applying
3,000 V of alternating current, the weight of granulation tissue
and levels of hydroxyproline increased significantly by 187 and 171%,
respectively (p<0.05). 2. By applying 3,000 V of alternating current
to rats on the low-protein diet supplemented with Eucommia ulmoides
leaves (0.75%), the weight of granulation tissue and levels of hydroxyproline
increased significantly within four weeks by 136 and 163%, respectively
(p<0.05 and 0.001, respectively). The results of the present study
suggest that adding Eucommia ulmoides leaves facilitates collagen
synthesis and formation of granulation tissue in aged rats. The fact
that levels of hydroxyproline in granulation tissue increased significantly
suggested that reduced collagen synthesis in aged rats was activated.
The formation of granulation tissue is indicative of the early stages
of wound healing, and this formation facilitates wound healing.Keywords: Aged rat, Eucommia ulmoides leaves, 3,000 V of alternating
current, Collagen synthesis, Granuloma formation